[rpmerf]

I do alot of electronics work, so there are a few simple tools I keep around.

Solder 2 wires onto a reverse light bulb(an LED and 670 ohm resistor works too), cover the bottom of the bulb in heat shrink tubing so it won't short if it touches something. Put a set of spade connectors on the ends. Made a bunch of different connectors to hook on the end, alligator clips are really useful. This is great because you can hook it up and muck around with things without having to hold a test light on something. with different connectors you can also connect it in line with something.

having a couple 2 foot long wires with alligator clips on both ends are useful also.

for cheap battery cable end, put a bit of copper pipe in a vice and drill a hole in it. I usually have a couple feet laying around that I can use.

NEVER underestimate having good grounds, especially in FI cars. I will run a couple extra 2 gauge cables between the battery block and body just to be sure.